Adult dominant segment polarity phenotype: loss of anterior portion of middle abdominal tergites and duplication of posterior tergite bristles.

Nervous system of homozygous embryos at stage 16 and 17 shows no gross abnormalities. Mutant larvae reach the third larval instar approximately one day later that wild type and pupariate three days after wild type. Most developmentally delayed larvae possess one or more amorphous melanotic tumours at various locations within the abdomen. Development stops during the mid-pupal phase.